Citation

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

The radiative capture of protons by [...] has been investigated using anticoincidence techniques down to a laboratory energy of 92 kev, but no new levels are found that would influence the cross section at stellar energies. An upper limit is placed on the strength of radiative capture by any missed levels. From several of the same targets used for the [...] measurements the yield of [...] radiation has been measured below 450 kev, and the cross sections of both reactions are extrapolated to stellar energies. The extrapolated cross section factor [...] at 25 kev C. M. proton energy is [...] kev-barn for the [...] reaction, and is [...] kev-barn for the [...] reaction. The equilibrium ratio by number of [...] in the CNO cycle is thus 4.1 [...] 0.7 at a temperature of [...] K.

The parameters of the resonance controlling the low energy cross section in the [...] reaction are determined -- a resonance energy of 555 kev and a reduced width of 570 kev. The experimental cross section is fitted with the Breit-Wigner single level formula and, for comparison, a fit based on the Humblet-Rosenfeld theory of nuclear reactions is attempted.

A new level was found in the [...] reaction at a resonance energy of 448.5 [...] 0.5 kev (7.966 Mev excitation) with a total width of less than 400 ev. Angular distribution measurements, combined with the results of [...] by other workers, lead to an assignment [...] for this resonance.